Apparatus for countercurrent contact of fluid materials



Sept. 19, 1950 .1. 0. LONG 2,523,126

APPARATUS FOR counmcumm comm or FLUID MATERIALS Filed Nov. 20, 1947 2 Sheets-Sheet 1 FIG. I

IN VE N 7' 0/? JbH/V D. Lon/6 8y [a 7 ATTOf/VEY J- D. LONG APPARATUS FOR COUNTERCURRENT CONTACT 0F FLUID MATERIALS Filed Nov. 20, 1947 Sept. 19, 1950 2 Sheets-Sheet 2 h u u m LIGHT Fl. U/D

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LIQUID LEVEL M w w 7% ATTORNEY P ed pt. 19, 1550 2,523,126

UNITED STATES PATENT OFFICE,

7 APPARATUS FOR COUNTERCURRENT CONTACT F FLUID MATERIALS John D. Long, Caracas, Venezuela, assignor to Standard Oil Development Company, a corporation of Delaware Application November 20, 1947, Serial No. 787,124 1 Claim. (Cl. 261-114) The present invention relates to a means for contacting fluids of substantially dissimilar specific gravity or character in countercurrent flow. More particularly, it relates to such a method ent invention may be obtained by employment of the present invention in the manner herein set forth.

The invention and its objects may be readily as practiced in countercurrent contact of liquids 5 understood from the following description when and vapors as in a fractionation or distillation read in conjunction with the accompanying tower, and by the use of Venturi type means for drawings in which the replacement of bubble cap elements in the Fig. 1 is a diagrammatic showing of a vertical plates or trays of such contacting means. In section through a portion of a countercurrent such operations it is an object of the invention contacting apparatus, to improve contacting efiiciency by dispersing the Fig. 2 is a plan view of a tray or plate in such heavier fluid in the lighter in contradistinction apparatus. to present methods, and particularly by dispers- Fig. 3 is an enlarged view in vertical section of ing the liquid in the gaseous medium when opthe contacting means according to this invenerating a fractionating or distillation tower. It tion, and is also an object to provide an apparatus for Fig. 4 is a showing similar to that of Fig l effecting countercurrent liquid to liquid contact of another form of contacting apparatus. by such Venturi means. Referring more specifically to the drawing, in At the present time, in the fractionation of a which similar parts are similarly identified, the heated gaseous medium, it is customary to pass numeral l designates a fractionation tower or the gaseous material upward through an elonother apparatus of like nature intended for gated vertical column or tower provided with a countercurrent contacting of fluids of dissimilar plurality of horizontally disposed, perforated specific gravities. Within the tower, a vertical plates or trays, while flowing a body of a liquid series of contact zones is provided by means oi medium downwardly over such trays at a predea vertical series of plates or trays 2 which are termin dr e and pth. The openings in each fitted in fluid tight relation to the tower walls, tray are provided with chimney portions and except that a segment of each plate has been covered by caps, known as bubble caps, supported removed to provide an opening or passageway by said chimney portions, which force dispersion from plate to plate, as at X. In locating the of the gas through the liquid flowing across the plates in the tower, it is preferred that the opentrays and maintained at a specified level thereon. ings be oppositely disposed so that, in a fluid Usually the liquid stream is directed in such flowing through the tower by way of such pasmanner as to create a side to side flow from one sageways, lateral flow from plate to plate will be plate to another downwardly through the column. induced. Means are provided to maintain a pre- This type of equipment has been used for many determined interface level between the fluid years, and by gradual improvement of design, phases passing through the tower, such' as a weirconsiderable improvements in efliciency have bafile member, at the plate edge of each opening been obtained. It has been found, however, that :0, consisting of a weir portion 3a and a baflie more eflicient contact between vapors or gases portion 32). Where the lighter of two fluids is and liquid is obtained by dispersion of a liquid 40 to be the dispersing medium for the heavier fluid, in a vapor or gas, than by dispersion of a gas or as where a liquid is to be dispersed in a vapor vapor in a liquid as accomplished by the use of for contact in a fractionating operation, the weir bubble-caps. To obtain the benefits of liquid in and baffle elements are disposed as shown in gas dispersion, the present invention provides Fig. l, but where, as in a solvent extraction means for dispersing a plate liquid in a stream process, it may be desired to disperse the lighter of gas flowing through openings in a fractionatof two fluids, such as an oil, in the heavier, such ing tower plate or tray provided with Venturi as phenol, the weir-baflle is disposed as shown in vents instead of bubble caps. Likewise, counter- Fig. 4. current liquid extraction processes utilize similar Dispersion of the one fluid in the other is accomplished mechanically under the influence of apparatus, and many of the benefits of the presgravimetric pressures, by means of Venturi elements 4 communicating with suitable perforations in the plates 2. When dispersing the heavier fluid in the lighter, these elements 4 are disposed over the perforations as shown in Fig. 1. when dispersing the lighter fluid in the heavier, they are disposed below the perforations as shown in Fig. 4. It is preferred that the Venturi elements 4 be of such length, and that the weir and baille portions to and 3b be so adjusted, as to permit the discharge ends of the elements 4 to open into a body of the dispersing fluid maintained in each contact zone by the baffle portions SD. A body of the fluid to be dispersed is maintained in smaller volume around the Venturi elements 4, and preferably not beyond the outlet thereof, by means of the weir portions 3a. Each of the Venturi elements 4 is provided with a plurality of passageways or inspirating tubes 5 opening radially outward from the throat 4a of the element 4 through the sidewalls thereof, and into communication with the space to be occupied by the fluid to be dispersed, the outer end of the tube 5 normally being submerged therein.

When operating, as illustrated by Fig. 1, with a vapor and a liquid, the elements 4 are preferably provided with deflectors l to prevent straightthrough flow of the vapors, or the liquid-vapor dispersion, from plate to plate. These deflectors are preferably of substantially conical shape and are mounted on spacer rods 6 secured to a flange 4b on the discharge end of the elements 4, in such manner that the apex of the deflector member extends into or toward the outlet of the element. As an additional precaution, it is also desirable that the elements 4 be so disposed on each plate as to avoid alignment of such elements on one plate with those on the plate above or below. Further, while the distribution of elements 4 over the total area of the plate may not be essentially critical, it is preferred that they be arranged so as to provide a minimum of interference with the flow across the plate of fluid to be dispersed. To this end it is preferred that the elements be disposed in uniform rows, i. e. that they have a square pitch, rather than in alternate rows, 1. e. having a triangular pitch. In such fashion the plate liquid gradient is reduced, and improved separation of phases is achieved, both of which are desirable in the use of elements of the character described. It is also considered desirable that the Venturi elements be spaced, one from another, by a distance not less than two element diameters.

In determining suitable dimensions for the Venturi elements 4, the same general dimensional relationships are required as for any Venturi device. In particular, it is considered that the diameter of the Venturi inlet may be taken as the controlling dimension, and in the service it is contemplated that inlet diameters of from one inch to four inches will be found most economical and practical. The length of the elements should be not substantially less than twice the inlet diameter, with the Venturi throat located at a distance from the inlet equal to approximately the total length of the element, the throat diameter being from about A to i the inlet diameter.

The inspirating tubes 5 should open outwardly through the element 4 at the narrowest part of the throat, being arranged circumferentially thereof. It is considered desirable that the diameter of these tubes 5 be not less than inch, to avoid plugging, and not more than the diameter of the throat 4a, and that these tubes Venturi inlet diameter 2 inches Element length 4 inches minimum Distance from inlet to throat. 1 inch Diameter of throat to 1 inch 1*; inch minimum Diameter of inspirating tubes.{ 1A inch maximum Spacing of inspirating tubes V to inch A fractionating tower according to the invention will operate in conventional fashion to the extent that a liquid medium, introduced at the top, will be permitted to flow downwardly through the tower over the successive plates in succession, while a gaseous medium, introduced at the bottom, is passed upwardly through the respective plates to contact the liquid flowing down. However, whereas in the conventional tower, the gaseous medium is dispersed in the liquid by the use of bubble cap elements, according to this invention the liquid is dispersed in the gas by means of the special Venturi elements, or jets illustrated and described. By virtue of the invention, lower liquid levels and volumes may be maintained on the respective plates, it being necessary merely to maintain a level sufficient to cover the comparatively small inspirating tubes, and in such operation the effect of vapor flow on the liquid gradient across the plates is substantially eliminated.

Although the invention has been described primarily with reference to an operation in which the heavier fluid is dispersed in the lighter fluid flowing upwardly through the tower I, and particularly a liquid dispersed in and by a vapor, not only may such an operation be performed with two liquids of dissimilar gravity, but also by modification of the apparatus as shown in Figure 4, the heavier liquid may be suitably utilized to accomplish similar liquid to liquid contact by dispersal of a lighter liquid. As may be noted from the drawings, the dispersing fluid is preferably the one supplied to the tower and maintained therein in greater volume than the one to be dispersed, although other factors may frequently determine volume, rate of flow, and manipulation of the respective phases. In any event, while the invention has been described with reference to specific utilization thereof, it is not intended that it shall be limited by such description, provided for the purpose of illustration, but only by the appended claim.

I claim:

In an apparatus for countercurrent contact of fluids of dissimilar gravity, including a tower vessel, a plurality of plate elements transversely of said vessel and forming therewith a vertical series of confined contact zones for said fluids in which they are maintained as substantially separate phases having an interface, and means for flowing a stream of one fluid laterally through said zone, a means for flowing another fluid substantially vertically through said zones, comprising substantially tubular conduit elements opening through each plate, said elements having inlet and outlet ends and extending from one zone into another communicating in each of said zones with the fluid phase flowing vertically through the tower, the outlet end of each element terminating beyond the interface between phases, a Venturi 5 throat in each element and a plurality of inspirating tubes opening radially outwardly from said throat through said element into said phase flowing laterally through the contact zones,

whereby the fluid flowing through said element 5 inspirates the other fluid into the element through said tubes, an annular flange portion at the outer end of said element, a plurality of vertical studs extending outwardly from said flange, and a substantially conical deflector element, having an annular base rim flange, engageable by said studs, and supported thereby in spaced relation to the flanged end of said tubular element with the apex end of said conical deflector extending toward the Venturi element, concentrically thereof.

JOHN D. LONG.

a 6 REFERENCES orrsn meet this -patent' STATES PATENTS Number Name Date 1,613,352 Kobernik Jan. 4, 1927 1,741,519 Hufl Dec. 31, 1929 1,918,005 Urquhart July 11, 1933 10 2,183,561 Hamblin Dec. 19, 1939 2,222,565, Kraft Nov. 19, 1940 2,327,993 Bragg Aug. 31, 1943 2,345,667 Hachmuth Apr. 4, 1944 

